Thrust augmenting and south suppressing apparatus and method

ABSTRACT

An aircraft jet engine is provided with an ejector nozzle which suppresses the jet noise and augments the thrust during takeoff and climb while also optimizing the thrust during cruise. The ejector nozzle is formed as a barrel or ring which is supported in operative position aft of the exhaust nozzle and defines, with the noxxle, inlet passage means for free stream air to enter and mix with exhaust gases in the mixing zone defined by the nozzle. Peripheral jet nozzle means inside the ring eject a peripheral jet stream which surrounds and accompanies the mixed gases passing therethrough, adding to the total thrust and further mixing the gases. Jet nozzle means is supplied with energized gas by conduits connected to the engine. Ejector ring is fixed in position and supported by conduits to form an integrated ejector nozzle. This is made possible by the use of the jet nozzle means which controls the effective nozzle profile and flow therethrough to minimize thrust loss in cruise to acceptable value.

Tontini June 19, 1973 THRUST AUGMENTING AND SOUTH SUPPRESSING APPARATUSAND METHOD [75] Inventor: Remo Tontini, San Diego, Calif.

[73] Assignee: Rohr Industries, Inc., Chula Vista,

Calif.

22 Filed: Aug. 25, 1971 21 Appl. No.: 174,629

Related US. Application Data [63] Continuation-impart of Ser. No.137,630, April 26, 1971, which is a continuation of Ser. No. 866,641,Oct. 15, 1969, abandoned.

Pavlin et al. 239/265.17 Medawar 239/265.l3

Primary Examiner-Lloyd L. King Attorney-George E. Pearson [5 7] ABSTRACTAn aircraft jet engine is provided with an ejector nozzle whichsuppresses the jet noise and augments the thrust during takeoff andclimb while also optimizing the thrust during cruise. The ejector nozzleis formed as a barrel or ring which is supported in operative positionaft of the exhaust nozzle and defines, with the noxxle, inlet passagemeans for free stream air to enter and mix with exhaust gases in themixing zone defined by the nozzle. Peripheral jet nozzle means insidethe ring eject a peripheral jet stream which surrounds and accompaniesthe mixed gases passing therethrough, adding to the total thrust andfurther mixing the gases. Jet nozzle means is supplied with energizedgas by conduits connected to the engine. Ejector ring is fixed inposition and supported by conduits to form an integrated ejector nozzle.This is made possible by the use of the jet nozzle means which controlsthe effective nozzle profile and flow therethrough to minimize thrustloss in cruise to acceptable value.

12 Claims, 21 Drawing Figures PAIENIEUM 1 sum swam? minim-1mm mum"! FIG.7

L9 zio 2 .1

q d mama nm FIGB NOZZLE PRESSURE RATIO TAKEOFF T EST CASE CONICAL TARENOZZLE ALT= 2,000 FT N.P.R-=I.9 l/8 SCALE JT8D MODEL I I I40 I50 I "'0lio I30 I00 INTEGRATED NOZZLE/EJECTOR WITH 30% PERIPHERAL FLOW- FIG. 9

ANGLE'FROM INLET, IN DEGREES THRUST AUGMENTING AND SOUTH SUPPRESSINGAPPARATUS AND'METHOD CROSS-REFERENCE TO RELATED APPLICATIONS Thisapplication is a continuation-in-part of patent application for ThrustControl and Sound Apparatus", Ser. No. 137,630, filed Apr. 26, 1971which is a Continuation of patent application for Thrust Control andSound Suppressing Apparatus, Ser. No. 866,641, filed Oct. 15, 1969, nowabandoned.

BACKGROUND OF THE INVENTION This invention lies in the field of gasturbine or jet engines which produce reaction thrust by the highvelocity rearward discharge of exhaust gases from the engines. In orderto obtain the maximum thrust from a simple engine a great deal of studyand calculation goes into the design of the exhaust nozzle, and for bestresults it must be tailored to the particular installation, taking intoaccount the weight, speed, and other operating characteristics of theairplane on which it is mounted.

One way of increasing the thrust of such an engine is to design it sothat the compressor delivers more air than the turbine uses, the excessflowing around the outside of the turbine and joining the turbineexhaust. The mixing of the two gases adds mass to the thrust producingstream and reduces the velocity and temperature thereof, which alsoreduces the noise level.

Another system which is used extensively includes the provision of anejector ring which is larger than the exhaust nozzle outlet and islocated aft of the nozzle. Free stream air enters the flow path betweenthe exhaust nozzle and the ring and mixes with the exhaust gas, and alsowith the fan air if the engine is of the fan type. All of the gases mixwithin the ring with the same general effects mentioned above.

To attain optimum thrust under varying flight conditions of power andspeed, the exhaust nozzle is-often designed with means to translate theejector ring to a stowed position, or to vary the throat area or thedischarge cone or both, and many problems arise because of the variousmoving parts which must operate reliably while being subjected to theflow of the very hot exhaust gas.

SUMMARY OF THE INVENTION The present invention is directed particularlyto the type of aircraft jet engine assembly which incorporates anejector ring with or without the addition of the fan air feature andwithout requiring translation of the ring. It improves the ejectoraction and makes it possible to use a shorter and lighter ejector ring.In addition, it augments the thrust and decreases the noise, and alsoallows the addition of mechanism which can perform reverse thrust andalso the function of a variable nozzle with simplicity and reliability.Furthermore, the ejector ring according to the invention optimizes flowconditions to minimize shock losses under cruise conditions.

Generally stated, and in presently preferred forms, the total apparatusincludes a jet engine having a rearwardly discharging exhaust nozzlewhich may be conical or of any other type commonly used, the enginebeing provided with the fan air feature if desired. An ejector ring islocated aft of the nozzle and preferably with its entrance end in thevicinity of the exit margin of the exhaust nozzle. Jet nozzle means arearranged peripherally around the inner wall of the ring intermediate itsends to discharge energized gas and form an auxiliary peripheral jetstream to surround and accompany the mixed gases flowing out of thering.

The jet nozzle means may be a plurality of discrete nozzles or a singleperipheral nozzle and may be supplied with gas under pressure by conduitmeans connected to the engine. However, in the preferred form, theforward portion of the ejector ring is hollow to serve as a plenumchamber and the jet nozzle means is in the form of a substantiallycontinuous slot through the inner wall of the ring through which gas isdischarged from the plenum chamber. The energized gas is delivered tothe plenum chamber by conduit means connected at their forward ends tothe exhaust nozzle and at their aft ends to the plenum chamber, and theymay carry turbine gas or fan air or both. They also serve as supportmeans to connect the ejector ring to the engine. The performance of thering is such that it need not be movably mounted for stowing anddeploying. Thus the conduits serve as rigid means to mount the ringfixedly with respect to the engine to constitute it an integratedejector nozzle.

The ejector ring provided with the peripheral jet nozzle means is highlyeffective to improve performance in all flight regimes such as landingand takeoff while also minimizing thrust loss at cruise. If desired inparticular installations, the trailing edge may be provided with movablevanes or flaps to modify the nozzle profile. The ejector ring, moreover,may employ thrust reverser which may also be adjusted slightly toprovide limited nozzle profile modification.

BRIEF DESCRIPTION OF THE DRAWINGS Various other advantages and featuresof novelty will become apparent as the description proceeds inconjunction with the accompanying drawings, in which:

FIG. I is a schematic side elevational view of an engine installationincorporating the apparatus of the invention, the ejector ring havingtrailing edge vanes or flaps;

FIG. 2 is an end elevatiorial view of the apparatus of FIG. 1 taken onthe line 2-2;

FIG. 3 is an enlarged schematic sectional view taken on line 33 of FIG.2;

FIG. 4 is a fragmentary schematic view in longitudinal section of anengine installation in which the apparatus of the invention is appliedto a conical exhaust nozzle;

FIG. 5 is a view similar to FIG. 4 showing a multiple tube exhaustnozzle;

FIG. 6 is a view similar to FIG. 4 showing a lobed exhaust nozzle;

FIG. 7 is a view similar to FIG. 4 showing a conical nozzle and a fanair duct;

FIG. 8 is a chart illustrating the thrust augmentation achieved with theapparatus of the invention;

FIG. 9 is a chart illustrating the reduction in perceived noise levelachieved with the apparatus of the invention;

FIG. 10 is a schematic view in side elevation of a simple conical nozzlewith a graphical illustration of the jet stream velocity profile;

FIG. 11 is a view similar to FIG. 10 with a simple ejector ring added;

FIG. 12 is a view similar to FIG. 11 with a lobed nozzle;

FIG. 13 is a view similar to FIG. 11 with the peripheral jet nozzle ofthe invention added;

FIG. 14 is a view similar to FIG. 13 with a lobed nozzle;

FIG. 15 is a view similar to FIG. 4 showing a conical nozzleincorporating an afterburner and air flaps;

FIG. 16 is a view similar to FIG. 4 showing the use of turbine gas andfan air separately in the ejector ring;

FIG. 17 is a schematic view in longitudinal section of a modified formof the apparatus mounted aft of the trailing edge of a wing;

FIG. 18 is a top plan view of the apparatus of FIG. 17;

FIG. 19 is a view similar to FIG. 17 showing the engine and apparatusforward of the trailing edge of a wing;

FIG. 20 is a side elevation of a structural embodiment of the nozzleconfiguration of FIG. 6 and including doors for thrust reversal anddiffusion angle modification; and

FIG. 21 is a graphical representation of the diffusion angle adjustmentof the doors.

DESCRIPTION OF PREFERRED EMBODIMENTS The assembly shown schematically inFIG. 1 includes a housing enclosing an engine 12 and a compressor 14driven by a turbine. A nozzle 16 is attached to the turbine to receiveexhaust gas therefrom and discharge it rearwardly from its exit margin18 which preferably lies in a plane perpendicular to the axis of thecompressor, engine and nozzle. A compressor may be designed to delivermore air than the turbine requires, and the excess flows rearwardlywithin housing 10 to discharge it at 20 into the nozzle where it mixeswith the turbine exhaust gas to add mass, cool the mixture, and lowerthe noise level.

An ejector ring 22, which is preferably annular, is mounted coaxiallyaft of the nozzle with its leading edge 24 preferably in about the sameplane as the exit margin 18 of the nozzle. The ring is substantiallylarger than the nozzle to provide an annular inlet flow passage 26 forfree stream air to enter and mix with the gases issuing from the nozzle.The intermediate section 28 of the ring defines the mixing zone wherethe free stream air meets the other gases, and the contour of the ringis completed by a trailing'section 30 comprising a plurality ofperipherally arranged flaps 32 pivoted at their forward ends by pivotmeans 34 to the aft or trailing edge of the intermediate section.

The intermediate section 28 of the ring is hollow to form an annularplenum chamber 36 as shown in FIG. 3, and the ring is mounted to theengine by a plurality of peripherally spaced conduits or tubes 38 which,as shown in FIG. 1, connect at their forward ends with the nozzleadjacent to the turbine and at their aft ends with the forward portionof the ring. The conduits receive exhaust gas or a mixture of exhaustgas and fan air from the engine and deliver it at high pressure to theplenum chamber.

Returning to FIG. 3, it will be seen that the plenum chamber is open atits trailing edge to form a plurality of peripherally arranged slots ora single peripheral slot 40 which discharges gas from the plenum chamberrearwardly in a substantially cylindrical auxiliary peripheral jetstream which surrounds the gas mixture issuing from the mixing zone andacts as a virtual rear ward continuation of the ejector ring. Thus itsurrounds and controls the mixture and causes further intimate mixing tofurther reduce the noise level.

More particularly, the aft end of ring 22 is formed with a wall 44 whichextends radially inwardly from the outer wall of said ring and thencurves in the downstream direction, the forward ends of flaps 32 beingdisposed between the aft ends of said wall 41 and said outer wall. Aflexible wall 42 is attached to the inner surface of the outer wall ofthe ring and to the forward ends of the flaps, and a flexible sheet 43is attached to the aft edge of said outer wall and extends over theforward portions of said flaps. Thus free stream air is prevented fromreaching the points on the flaps where exhaust gas, or a mixture ofexhaust gas and fan air, flows from slot 40. Since the inner surfaces ofthe flaps are substantially in alignment with the slot, the peripheraljet stream flowing from the latter attaches to said flaps by virtue ofthe Coanda effect. Because of this attachment, the peripheral jet streamwill follow the adjacent walls of the flaps and as they are swung towardor away from the axis of the ring, the jet stream will form a rearwardlyconvergent or divergent cone. Since the jet stream acts as acontinuation of the ring it effectively changes the contour of the ringto provide any desired throat configuration.

The flaps may be adjusted to any desired angle in flight by means of oneor more servo motors 44 which act through links 45 pivotally connectedat 46 to control horns 48. A streamlined cover 50 is provided for eachservo motor. All of the flaps are mounted in overlapping relation sothat there is no peripheral gap at any angle of adjustment. Theoverlapping relation also insures that they will all move in unison.

An installation incorporating the invention in its simplest form isshown schematically in FIG. 4, in which a jet engine, not shown, isprovided with a rearwardly discharging exhaust nozzle 60 having aconical exit section 62 terminating in a trailing edge 64. An ejectormember 66 commonly referred to as a ring or nozzle or barrel, is locatedin operative position aft of the exhaust nozzle 60, with its entranceend 68 located adjacent to the exit plane of the nozzle, its exact foreand aft position being determined for each installation in accordancewith operating requirements. The exit end or trailing edge 70 definesthe discharge passage for all of the thrust producing gas stream. Thering is generally hollow and is defined by inner and outer walls 72 and74.

The leading end 68 is spaced from the conical section 62 to define inletpath means 76 for the flow of free stream air into the mixing zone 78defined by the interior of the ejector ring, where it meets and mixeswith the turbine gas exiting from nozzle section 62 as they passtogether through the ejector ring. The free stream air adds mass to theturbine gas and the velocity of the total stream is reduced. Inaddition, since the free stream air is much cooler, the temperature ofthe final gas mixture is greatly reduced. These factors augment thethrust and substantially reduce the noise level at exit 70.

While these are desirable improvements resulting from the presentlyknown and used ejector barrel constructions, they still leave much to bedesired. The efficiency must be increased and the noise level must befurther decreased. The conventional ejector barrel produces anunacceptable thrust loss at cruise because of the shock conditionresulting from the very high ratio of pressure and flow speeds betweenthe nozzle gases and the entering free air stream. Consequently,conventional ejector barrels must be retracted for cruise with asubstantial penalty in the form of weight, complication, and maintenancecost of the components required to stow and deploy the barrel andsupport it adequately in deployed position.

The present invention overcomes these disadvantages by the provision ofauxiliary jet nozzle means peripherally arranged around the inner wall72 of the ejector ring intermediate its ends to discharge energized gasaround the periphery of the gaseous mixture flowing through the ring.The jet nozzle means may be a plurality of separate nozzles or a singlenozzle and may be a separate component mounted in the passage and may besupplied by any conduit means carrying high pressure gas to it from theexhaust nozzle. However, in its most preferred form, it comprises acontinuous peripheral slot 80 through the inner wall 72 andcommunicating with the interior of the ring.

Separate plenum means may be mounted in the ring but preferably aperipheral partition wall 82 extends entirely around the ring and fromits inner wall 72 to its outer wall 74to form plenum chamber 84 withinthe forward portion of the ring. Conduit means 86 are connected at theirforward ends to the exhaust nozzle and at their aft ends to the plenumchamber to supply pressurized exhaust gases to the jet nozzle means 80.The ring is maintained in the deployed position at all times and theconduits 86 are used to rigidly support it in such position.

Partition 82 is preferably formed to converge rearwardly as shown, withthe result that the gases issuing from the jet nozzle means have asubstantial rearward component. The peripheral outflow performs severalimportant functions. It forms a gaseous shield around the jet streamwhich serves as a virtual elongation of the ring and reduces noiseemission at angles to the thrust axis. It energizes and speeds up theboundary layer to improve the free air stream inflow, in effect pumpingin additional air at a higher speed and decreasing the shock effect. Byincreasing the speed of the radially outer portion of the jet stream, itimproves the velocity profile as will be discussed later with respect tosome of the other figures in the drawings. It also produces or controlsthe effective nozzle profile and effective exit area as indicated bybroken lines 88. By proper advance testing and design the configurationof the jet nozzle slot can be selected so that the virtual nozzleprofile and exit area will approach the ideal with the flow and pressurecharacteristics of cruising flight.

The installation shown in FIG. 5 is substantially the same as that ofFIG. 4 but the exhaust nozzle is of the multiple tube type in whichnozzle 90 is provided with a plurality of tubes 92 which are radiallyand peripherally spaced from each other to divide the exhaust flow intoa plurality of individual streams, the nozzle area between the tubesbeing closed off. Ring 66 may be connected to and supported by two ormore of the radially outermost tubes which will conduct gases from thenozzle to the plenum chamber 84. The inlet flow path 76 is definedbetween ring 66, nozzle 90, and the outer tubes, and the total operationis the same as that de-- scribed with reference to FIG. 4.

The installation of FIG. 6 is also substantially the same as that ofFIG. 4 but in this case the nozzle 94 is of the well known lobe type inwhich the aft portion of the nozzle is formed into a plurality ofperipherally spaced radially and axially extending lobes 96 definingvalleys 98 between them which serve as the inlet flow paths for freestream air. Ring 66 may be mounted by conduits 100 which will conductgases from the nozzle to plenum chamber 84, or the ring may be mountedto the trailing edges of the lobes and open to at least some of them toreceive energized gases.

The installation of FIG. 7 is similar to that of FIG. 4 but in this casethe engine is of the fan type and is provided with a nozzle 102 having atrailing edge 104. A fan air passage 106 is located adjacent to nozzle102 and may extend partially or completely around the nozzle as shown.It extends aft of the nozzle and has an exit at 108 where the freestream air joins and mixes with the turbine gas in mixing chamber 78.The aft portion of passage 106 is peripherally interrupted to defineinlet flow paths 76 for free stream air and is connected to ring 66 tosupport it and to supply fan air under pressure to plenum chamber 84 forthe jet nozzle means 80. The operation is the same as in FIG. 4 exceptthat the energized gas for the jet nozzle means is fan air instead ofturbine gas.

The charts of FIGS. 8 and 9 show the improved performance of a jetengine equipped with the apparatus of the invention as opposed toprevious types. In FIG. 8 it will be seen that throughout the normalrange of nozzle pressure ratios an ejector ring equipped with theperipheral jet nozzle means produces a consistent and very substantialincrease in thrust augmentation. In FIG. 9 it will be seen that not onlydoes the ejector ring of the invention reduce the perceived noise levelsubstantially below that of a conventional nozzle, but that the leveldrops off rapidly with increase in angle from the inlet. This means thatthe level is quite high only in directions more directly to the side ofa passing airplane, thus greatly shortening the duration time ofexposure of any'fixed point to such high level. This is referred toeffective perceived noise level.

FIGS. 10 to 13 illustrate the effects of different configurations on thevelocity profile of the jet stream. FIG. 10 shows a plain conical ortare nozzle 110. The high friction drag of the nozzle wall greatlyreduces the velocity of the peripheral portion of the stream while notaffecting the axial portion. This results in the velocity profile 112having a very high axial peak 114. The noise level is high and thethrust is conventional. In FIG. 11, a conventional ejector barrel 116 isadded to bring in free stream air and mix it with the primary stream.The added mass reduces the maximum axial velocity peak 118 and increasesthe velocity of the pe ripheral portion as indicated at 120, thusflattening the profile to some extent, increasing the thrust anddecreasing the noise level. In FIG. 12, the same ejector barrel isapplied to a nozzle 122 having a lobed or daisy aft portion 24 whichacts in a well known manner to reduce the peak and increase theperipheral portion of the jet stream. The action of the ejector barrelincreases this effect and the result is the profile having a much lowerpeak 126 and higher peripheral portion 128.

In FIG. 13, a conical nozzle 130 is provided with an ejector ring 132having peripheral jet nozzle means 134 which function in the mannerpreviously described.

The resulting velocity profile has a peak 136 which is only slightlyhigher than the peak 126 obtained with a lobed nozzle and a conventionalejector barrel, while the peripheral portion 138 is much higher thanperipheral portion 128. Thus the improved ejector ring is as effectivewith a conical nozzle as a plain ejector barrel is with a lobed or daisynozzle. Finally, in FIG. 14, ring 132 is applied to nozzle 140 having alobed aft portion 142 and the result is an almost flat profile having anaxial peak 144 and peripheral portion 146 which are almost identical.The net effect is maximum thrust with minimum noise.

The installation shown in FIG. is basically similar to that of FIG. 4,and the ejector ring 66 is mounted and operates in the same manner.Nozzle 148 has a trailing edge 150, and an afterburner 152 is locatedwithin the nozzle upstream of the trailing edge. A plurality of fore andaft extending conduits 154 are peripherally spaced to define inlet flowpaths 76, and they support ring 66 in position and also supplypressurized gas from the exhaust nozzle to plenum chamber 84. A door 156is provided between each two conduits and is pivoted at 158 at itsforward end to swing to stowed position lying against the nozzle anddeployed position blocking one of the paths 76 to prevent reverse flowunder the extremely high pressure of afterburner operation. When theafterburner is not in use and the doors are stowed, the apparatusoperates in the manner previously described.

The apparatus of FIG. 16 is equipped with substantially the same ejectorring 66 as in FIG. 4 but is modified to incorporate an additionalfeature. Ring 66 is provided at each side with a partition 160 extendingfrom inner to outer wall to divide the plenum chamber into two separatecompartments, upper compartment 162 and lower compartment 164. Nozzle166 is connected by conduit 168 to compartment 164 to deliver turbinegas to the compartment and to the lower half of jet nozzle means 80. Fanair passage 170 partially or completely surrounds nozzle 166 anddischarges part of the fan air into the mixing zone 78 to mix with theturbine gas in the usual manner. It is also connected by conduit 172 tothe upper compartment 162 to deliver fan air to the compartment and onto the upper half of jet nozzle means 80.

With the construction just described, the ejector ring produces acomplete peripheral gaseous shield surrounding the jet stream just as inthe previous constructions, but in this case one half of the shield ismuch hotter and at a higher energy level than the other half. One ofthese halves is more effective to reflect sound waves inwardly towardthe other gas side and to refract the sound waves which pass through it.The reflected sound waves pass more readily through one half of theshield and away from the observer. Thus the noise which was alreadysignificantly reduced by the action of the ejector ring 66 is furtherreflected and refracted so that the net emission toward the ground isnoticeably reduced.

FIGS. 17 and 18 depict a slightly modified configuration in which theapparatus of the invention may be used to enhance the aerodynamicfunctions of an airplane on which it is mounted. An engine 173 similarto the engine of FIG. 4 is mounted beneath an airplane wing 174 by apylon 176 in such chordwise location as to place the exit plane 178 ofthe nozzle slightly aft of the trailing edge of the wing, so that theair streams passing over the upper and lower surfaces of the wing andits depressed dual or tandem flaps 180, 182 are directed toward the exitplane 178.

The ejector ring 184 is of the same general nature as the ring of FIG.4, having a plenum chamber 186 and jet nozzle means 188, and beingconnected to the exhaust nozzle of engine 173, by oppositely disposedconduits 190 which support the ring in place and conduct energized gasesfrom the engine to the plenum chamber. Additional conduits 192 open intoring 184. The ring is rectangular and extends along a substantialspanwise distance. The conduits 190 and 192 are flared, conduit 192being quite wide while the conduits 190 are fairly narrow to reduceinterference with the air stream flowing down from the wing. The ejectorring operates in the same way as previously described, and its ejectoraction energizes the air flow over the wing and flaps to greatlyincrease their lifting effect. The ejector ring may further be providedwith trailing edge flaps 194 which may be depressed to deflect the jetstream and produce additional lift.

Alternatively, the engine may be located forward in the conventionalposition, with the jet stream acting to improve the operation ofchordwise separated high lift flaps. In FIG. 19, the engine 173 extendsforward of the leading edge of wing 196 and is attached thereto by pylon198. The ejector ring 184 takes the same rectangular form as in FIGS. 17and 18 and may use the same conduit supports 19 0 and addition ofconduits 192. The position of the engine is such that the entire ejectorring including its flaps 194 is forward of the chordwise separated highlift wing flaps 200 and 202. When maximum lift is desired, flaps 200 and202 are lowered as shown and flaps 194 of the ejector ring are raised asshown. The jet stream from the ejector ring therefore is deflectedupward to flow through the slots and over the upper and lower surfacesof flaps 200 and 202 to energize their boundary layers and enhance theirtotal lifting effect. In addition to such operation, the position offlaps 194 may be modulated selectively to adjust the diffusion angle toachieve maximum performance in certain flight modes.

Referring to FIG. 20, there is shown a structural embodiment 204 of theintegrated ejector-nozzle of FIG. 6 which features a daisy type nozzlein conjunction with the ejector peripheral nozzle. The integratedejector nozzle 204 is a unitary structure which is attachable as a unitto the engine exhaust face F of an engine such, for example, as thePratt and Whitney JT8D turbofan engine. Such unitary structure is shownto include a combined thrust reverser and feathering feature, presentlyto be described.

Passages 206 are formed in the ejector barrel 66 extending through itsinner and outer walls, and blocker door 208 are located in such passagesand pivoted at 210 on transverse axes. The doors are swingablerearwardly and toward each other to block rearward flow of the main jetand divert the gases laterally out through passages 206 to producereverse thrust. Details of the thrust reverser mechanism are not a partof the present invention but are fully disclosed in U.S. Pat. No.3,531,049 of F. Horn and U.S. Pat. No. 3,532,275 of F. I-Iom et al.

Doors 208 may be used for feathering" by which is meant adjustment ofthe diffusion angle of the issuing jet. In stowed position of the doorsas shown in full lines in FIG. 20, their inner surfaces 212 are disposeddivergently at an angle 0 with respect to the longitudinal centerline214 of the ejector barrel, as best seen in FIG. 21. The correspondingaft inner wall of the ejector barrel diverges at the same angle 0. Forfeathering, the portion of the ejector wall constituted by the doorsurfaces 212 may be set at some angle less than by adjusting the doorsslightly without breaking the seat with the barrel openings 206. Thus,the reverser doors may serve to limited extent to provide the featheringfunction of flaps 32 of FIGS. 1 to 3.

Having thus described the invention, what is claimed as new and usefuland is desired to be secured by U. S. Letters Patent is:

ll. Apparatus for augmenting the thrust and suppressing the exhaustnoise of a jet engine having a rearwardly discharging exhaust nozzle,comprising: an ejector ring comprising an inner and outer wall andhaving an entrance end and an exit end; the ejector ring being locatedin operative position aft of the exhaust nozzle with its entrance endadjacent to the nozzle exit and spaced at least in part from the nozzleto define inlet path means for the flow of free stream air; the ringdefining a mixing zone for the free stream air and the gas streamissuing from the nozzle; a plenum chamber within the ejector ring;conduit means to conduct gas under pressure from the engine to theplenum chamber, the plenum chamber being in the forward portion of theejector ring and being formed by the forward portions of the inner andouter walls of the ejector ring and by peripheral partition meansextending between the inner and outer walls of the ejector ring; andauxiliary jet nozzle means peripherally arranged around the inner wallof the ejector ring intermediate its ends to discharge energized gasfrom the plenum chamber into the ejector ring around the periphery ofthe gaseous mixture flowing through the ejector ring.

2. Apparatus as claimed in claim 1; the jet nozzle means comprising asubstantially continuous peripheral slot through the inner wall of theejector ring in flow communication with the interior of the ring.

3. Apparatus as claimed in claim 1; the exhaust nozzle being a simpleconical nozzle.

4. Apparatus as claimed in claim 1; the exhaust nozzle comprising aplurality of discrete longitudinally directed tubes separating theexhaust into a plurality of separate streams for mixing with the freestream air in the mixing zone.

5. Apparatus as claimed in claim 1; the exhaust nozzle being in the formof a plurality of peripherally spaced radially and longitudinallyextending lobes opening rearwardly and defining inlet paths between themfor flow of free stream air.

6. Apparatus as claimed in claim 1; including passages in the aftportion of the ejector ring downstream of the jet nozzle means andextending through the inner and outer walls of the ejector ring; and avane pivotally mounted in each passage on a transverse axis; the vanesbeing swingable in unison about their axes through limited angles tomodify the nozzle profile and exit area of the ejector ring, and throughsubstantially greater angles into proximity with each other and with theejector ring axis to serve as thrust reverser doors to block rearwardflow of the gases from the mixing zone'and divert them laterally outthrough the passages to produce reverse thrust.

7. Apparatus as claimed in claim 1; the engine being of the fan typewith a central nozzle to direct the turbine discharge into the radiallycentral portion of the ejector ring; a fan air passage adjacent to thecentral nozzle; the forward portion of the ejector ring comprisdinallyextending conduits connecting the ejector ring to the nozzle andproviding between them a plurality of inlet passages between the nozzleand the ejector ring for flow of free stream air; and a door hinged atits forward end for each inlet passage adapted to be stowed for normalflight operation clear of the inlet passage and to be deployed to blockthe passage for afterburner operation.

9. Apparatus as claimed in claim 1; the engine includ ing a centralnozzle for the discharge of turbine gas and a fan air passage adjacentto the central nozzle; the forward portion of the ejector ring beinghollow to define an annular plenum chamber; a radial partition extendingacross the chamber at each side to divide it into compartments; the jetnozzle means consisting of a substantially complete peripheral slotextending through the inner wall of the ejector ring and in flowcommunication with the compartments; a conduit connecting the fan airpassage with one of the compartments, and a conduit connecting thecentral nozzle with another of the compartments.

10. Apparatus for augmenting the thrust and suppressing the exhaustnoise of a jet engine located on an airplane wing provided with trailingedge lift increasing flaps; the engine having a rearwardly dischargingexhaust nozzle with an exit plane adjacent to the trailing edge of thewing, comprising: an integrated ejector nozzle in the form of an ejectorring having an entrance end and an exit end; the ejector ring beinglocated aft of the exhaust nozzle with its entrance end adjacent to thenozzle exit and below and adjacent to the trailing edge of the wing andspaced at least in part from the nozzle to define inlet path means forthe flow of free stream air including air passing over the adjacent wingsurfaces; the ring defining a mixing zone for the free stream air andthe gas stream issuing from the nozzle; auxiliary jet nozzle meansperipherally arranged around the inner wall of the ejector ringintermediate its ends to discharge energized gas thereinto around theperiphery of the gas mixture flowing through the ring and increase theflow of free stream air over the adjacent wing flaps; and means tosupply gas under pressure to said jet nozzle means.

111. Apparatus as claimed in claim 10; the aft portion of the ejectorring being provided with pivoted vanes swingable upward and downward toproduce vertical components in the issuing jet stream.

12. Apparatus for augmenting the thrust and suppressing the exhaustnoise of a jet engine located on an airplane wing provided with trailingedge lift increasing flaps deployable to chordwise spaced positions; theengine having a rearwardly discharging exhaust nozzle with an exit planesubstantially forward of the flaps, comprising: an integrated ejectornozzle in the form of an ejector ring having an entrance end and an exitend; the ejector ring being located aft of the exhaust nozzle with itsentrance end adjacent to the nozzle exit and its exit end forward of theflaps; the entrance end being spaced at least in part from the nozzle todefine inlet under pressure to said jet nozzle means; the aft portion ofthe ejector ring being provided with pivoted vanes swingable upward todirect the issuing gas stream toward and over the surfaces of thedeployed flaps to enhance their lift producing effect.

1. Apparatus for augmenting the thrust and suppressing the exhaust noiseof a jet engine having a rearwardly discharging exhaust nozzle,comprising: an ejector ring comprising an inner and outer wall andhaving an entrance end and an exit end; the ejector ring being locatedin operative position aft of the exhaust nozzle with its entrance endadjacent to the nozzle exit and spaced at least in part from the nozzleto define inlet path means for the flow of free stream air; the ringdefining a mixing zone for the free stream air and the gas streamissuing from the nozzle; a plenum chamber within the ejector ring;conduit means to conduct gas under pressure from the engine to theplenum chamber, the plenum chamber being in the forward portion of theejector ring and being formed by the forward portions of the inner andouter walls of the ejector ring and by peripheral partition meansextending between the inner and outer walls of the ejector ring; andauxiliary jet nozzle means peripherally arranged around the inner wallof the ejector ring intermediate its ends to discharge energized gasfrom the plenum chamber into the ejector ring around the periphery ofthe gaseous mixture flowing through the ejector ring.
 2. Apparatus asclaimed in claim 1; the jet nozzle means comprising a substantiallycontinuous peripheral slot through the inner wall of the ejector ring inflow communication with the interior of the ring.
 3. Apparatus asclaimed in claim 1; the exhaust nozzle being a simple conical nozzle. 4.Apparatus as claimed in claim 1; the exhaust nozzle comprising aplurality of discrete longitudinally directed tubes separating theexhaust into a plurality of separate streams for mixing with the freestream air in the mixing zone.
 5. Apparatus as claimed in claim 1; theexhaust nozzle being in the form of a plurality of peripherally spacedradially and longitudinally extending lobes opening rearwardly anddefining inlet paths between them for flow of free stream air. 6.Apparatus as claimed in claim 1; including passages in the aft portionof the ejector ring downstream of the jet nozzle means and extendingthrough the inner and outer walls of the ejector ring; and a vanepivotally mounted in each passage on a transverse axis; the Vanes beingswingable in unison about their axes through limited angles to modifythe nozzle profile and exit area of the ejector ring, and throughsubstantially greater angles into proximity with each other and with theejector ring axis to serve as thrust reverser doors to block rearwardflow of the gases from the mixing zone and divert them laterally outthrough the passages to produce reverse thrust.
 7. Apparatus as claimedin claim 1; the engine being of the fan type with a central nozzle todirect the turbine discharge into the radially central portion of theejector ring; a fan air passage adjacent to the central nozzle; theforward portion of the ejector ring comprising a plenum chamberflowconnected to the jet nozzle means; the entrance end of the ejectorring being in flow communication with the fan air passage to receive atleast a portion of the fan air for discharge through the jet nozzlemeans.
 8. Apparatus as claimed in claim 1; the engine being providedwith an afterburner located within the exhaust nozzle; a plurality ofperipherally spaced longitudinally extending conduits connecting theejector ring to the nozzle and providing between them a plurality ofinlet passages between the nozzle and the ejector ring for flow of freestream air; and a door hinged at its forward end for each inlet passageadapted to be stowed for normal flight operation clear of the inletpassage and to be deployed to block the passage for afterburneroperation.
 9. Apparatus as claimed in claim 1; the engine including acentral nozzle for the discharge of turbine gas and a fan air passageadjacent to the central nozzle; the forward portion of the ejector ringbeing hollow to define an annular plenum chamber; a radial partitionextending across the chamber at each side to divide it intocompartments; the jet nozzle means consisting of a substantiallycomplete peripheral slot extending through the inner wall of the ejectorring and in flow communication with the compartments; a conduitconnecting the fan air passage with one of the compartments, and aconduit connecting the central nozzle with another of the compartments.10. Apparatus for augmenting the thrust and suppressing the exhaustnoise of a jet engine located on an airplane wing provided with trailingedge lift increasing flaps; the engine having a rearwardly dischargingexhaust nozzle with an exit plane adjacent to the trailing edge of thewing, comprising: an integrated ejector nozzle in the form of an ejectorring having an entrance end and an exit end; the ejector ring beinglocated aft of the exhaust nozzle with its entrance end adjacent to thenozzle exit and below and adjacent to the trailing edge of the wing andspaced at least in part from the nozzle to define inlet path means forthe flow of free stream air including air passing over the adjacent wingsurfaces; the ring defining a mixing zone for the free stream air andthe gas stream issuing from the nozzle; auxiliary jet nozzle meansperipherally arranged around the inner wall of the ejector ringintermediate its ends to discharge energized gas thereinto around theperiphery of the gas mixture flowing through the ring and increase theflow of free stream air over the adjacent wing flaps; and means tosupply gas under pressure to said jet nozzle means.
 11. Apparatus asclaimed in claim 10; the aft portion of the ejector ring being providedwith pivoted vanes swingable upward and downward to produce verticalcomponents in the issuing jet stream.
 12. Apparatus for augmenting thethrust and suppressing the exhaust noise of a jet engine located on anairplane wing provided with trailing edge lift increasing flapsdeployable to chordwise spaced positions; the engine having a rearwardlydischarging exhaust nozzle with an exit plane substantially forward ofthe flaps, comprising: an integrated ejector nozzle in the form of anejector ring having an entrance end and an exit end; the ejector ringbeing located aft of the exhaust nozzle with its entrance enD adjacentto the nozzle exit and its exit end forward of the flaps; the entranceend being spaced at least in part from the nozzle to define inlet pathmeans for the flow of free stream air; the ring defining a mixing zonefor the free stream air and the gas stream issuing from the nozzle;auxiliary jet nozzle means peripherally arranged around the inner wallof the ejector ring intermediate its ends to discharge energized gasthereinto around the periphery of the gas mixture flowing through thering; and means to supply gas under pressure to said jet nozzle means;the aft portion of the ejector ring being provided with pivoted vanesswingable upward to direct the issuing gas stream toward and over thesurfaces of the deployed flaps to enhance their lift producing effect.